Device and method for preparing carbon materials by pyrolysis and graded utilization of biomass

Abstract

A device for preparing carbon materials by pyrolysis and graded utilization of biomass includes a first tube furnace, a degassing mechanism and a second tube furnace. A first air inlet is in communication with an air outlet end of a first nitrogen bottle. A first air outlet of the first tube furnace is in communication with an air inlet end of the degassing mechanism, and the degassing mechanism is capable of absorbing water-soluble gas in pyrolysis gas. The second tube furnace has a second air inlet and a second air outlet, and the second air inlet is in communication with an air outlet end of the degassing mechanism, and the degassing mechanism is capable of sending water-insoluble gas in the pyrolysis gas into the second tube furnace and forming biochar by vapor deposition.

What is claimed is: 
     
         1 . A device for preparing carbon materials by pyrolysis and graded utilization of biomass, comprising:
 a first tube furnace, wherein the first tube furnace is internally placed with biomass raw materials, and has a first air inlet and a first air outlet, and the first air inlet is in communication with an air outlet end of a first nitrogen bottle;   a degassing mechanism, wherein the first air outlet of the first tube furnace is in communication with an air inlet end of the degassing mechanism, and the degassing mechanism is capable of absorbing water-soluble gas in pyrolysis gas; and   a second tube furnace, wherein the second tube furnace has a second air inlet and a second air outlet, the second air inlet is in communication with an air outlet end of the degassing mechanism, vapor deposition catalysts are placed in the second tube furnace, and the degassing mechanism is capable of sending water-insoluble gas in the pyrolysis gas into the second tube furnace and forming biochar by vapor deposition in the second tube furnace.   
     
     
         2 . The device according to  claim 1 , wherein a temperature of the first tube furnace is 450-600° C., and a temperature of the second tube furnace is 700-900° C. 
     
     
         3 . The device according to  claim 1 , wherein the degassing mechanism comprises:
 a first degassing membrane, wherein the first degassing membrane is made of hollow fibers, an upper end of the first degassing membrane has a first water inlet, and a lower end of the first degassing membrane has a first water outlet; an outer surface of the first degassing membrane is provided with a first gas flow channel, and two ends of the first gas flow channel are respectively in communication with the first air outlet and the second air inlet through first connecting ends;   a water tank in communication with the first water outlet; and   a second degassing membrane, wherein the second degassing membrane is made of hollow fibers, an upper end of the second degassing membrane has a second water outlet, and a lower end the second degassing membrane has a second water inlet; an outer surface of the second degassing membrane is provided with a second gas flow channel, and the second gas flow channel is in communication with atmosphere; and the first water inlet is in communication with the second water outlet via a connecting pipeline, the water tank is in communication with the second water inlet via the connecting pipeline, and a water pump is arranged on the connecting pipeline.   
     
     
         4 . The device according to  claim 3 , wherein two ends of the second gas flow channel are respectively in communication with a second nitrogen bottle and a vacuum pump through second connecting ends. 
     
     
         5 . A method for preparing carbon materials by pyrolysis and graded utilization of biomass, using the device according to  claim 3 , comprising following steps:
 S 1 : preparing for pyrolysis: crushing and drying the biomass raw materials, and then placing into the first tube furnace, and placing the vapor deposition catalysts into the second tube furnace;   S 2 : preheating: opening the first nitrogen bottle, and setting temperatures of the first tube furnace and the second tube furnace;   S 3 : pyrolyzing: enabling the biomass raw materials to be pyrolyzed in the first tube furnace so as to form the biochar and generate the pyrolysis gas, and starting the water pump to enable water in the water tank to circulate in the first degassing membrane, the second degassing membrane and the connecting pipeline so as to form circulating water;   S 4 : reforming gas: enabling the pyrolysis gas to flow from the first tube furnace into the first gas flow channel, forming a positive pressure difference between the first gas flow channel and the first degassing membrane, enabling the water-soluble gas in the pyrolysis gas to pass through the hollow fibers of the first degassing membrane and dissolve into the circulating water; and enabling the circulating water with the water-soluble gas to flow into the second degassing membrane, forming a reverse pressure difference between the second degassing membrane and the second gas flow channel, enabling the water-soluble gas to pass through the hollow fibers of the second degassing membrane and enter the second gas flow channel, and discharging into the atmosphere along the second gas flow channel; and   S 5 : performing vapor deposition: enabling the water-insoluble gas to flow into the second tube furnace, converting to form the biochar through the vapor deposition catalysts in the second tube furnace, and discharging waste gas, after the vapor deposition, into the atmosphere from the second air outlet.